Long-Term Evolution (LTE) is a standard for wireless communication of high-speed data for mobile phones and data terminals. It is based on the Global System for Mobile Communications (GSM)/Enhanced Data Rates for GSM (EDGE) and Universal Mobile Telecommunications System (UMTS)/High Speed Packet Access (HSPA) network technologies, but increasing the capacity and speed using a different radio interface together with core network improvements.
LTE Advanced in unlicensed spectrum (LTE-U) refers to a proposal to deliver LTE with small cells using unlicensed (e.g., 5 GHz) spectrum. LTE-U devices may wirelessly transmit and receive data using unlicensed and/or licensed spectrum. By tapping into the spectrum resources of the unlicensed bands, network operators may potentially obtain greater throughput and user satisfaction.
Unlike the use of licensed spectrum, however, with the use of unlicensed spectrum, the unlicensed spectrum resources may need to be simultaneously shared with multiple network operators and with traditional network access points (e.g., WiFi APs) that use the unlicensed spectrum. For example, an LTE-U system that uses the 5 GHz unlicensed spectrum may need to coexist with LTE-U base stations associated with other carriers and with traditional WiFi access points.